Pay-per-call premium API access on Base via x402 — $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. The site hosts a broad catalog of pay-per-request APIs spanning data & analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are priced at $0.02 per request, settled in USDC on the Base network.
The specific resource `/api/v1/payments/198` is listed as "Premium API Access" and returns a valid x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals), which equals $0.02. Payment is made via the x402 exact scheme — no API keys, no rate limits, and no subscriptions required. The endpoint accepts POST requests and returns application/json.
Documentation is extremely sparse: the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawled material. The actual functionality behind this particular endpoint path (`/payments/198`) is unclear — it may be a generic premium access gate or a specific resource. Prospective users should test with a small payment to discover the response format.
Capabilities
Use cases
- —Accessing premium API resources without traditional API key registration
- —Making one-off paid API calls settled in USDC on Base
- —Agent-driven programmatic access to paid endpoints via x402 protocol
Fit
Best for
- —Developers who want instant API access without signup or subscriptions
- —AI agents that can settle x402 payments autonomously on Base
- —Users comfortable paying per-request in USDC
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Users without access to USDC on the Base network
Quick start
# Send a POST with x402 payment header to access the endpoint
curl -X POST https://lowpaymentfee.com/api/v1/payments/198 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, documentation is essentially nonexistent — all doc/pricing/README pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, and no examples. The actual functionality behind /api/v1/payments/198 is not described beyond the generic label 'Premium API Access'.
Warnings
- —No documentation available — docs, pricing, API, and README pages all render only 'Connect wallet'
- —No OpenAPI or schema specification found
- —The actual functionality and response format of /api/v1/payments/198 is unknown
- —No request body schema or example responses are documented
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/payments/198
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The site offers APIs across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 with 6 decimalshttps://lowpaymentfee.com/api/v1/payments/198